China has requested Malaysia to verify rumors that the missing Malaysia Airlines flight MH370 may have turned back from its scheduled course before vanishing.

"We have send requests to the Malaysian side through diplomatic channels, asking them to check up on rumors right away and inform China of all information available," said Chinese Foreign Ministry spokesman Qin Gang in a written statement.

A Malaysian military official told a press conference on Sunday the missing flight may have changed route and turned back from its scheduled course before disappearing Saturday.

However, earlier on Wednesday, Malaysia's Air Force Chief Gen. Rodzali Daud denied a report that military radar had tracked MH370 flying over the Strait of Malacca, although he did not rule out the possibility that the aircraft turned back before it vanished from radar screens.

Based on this possibility, multinational search operation to locate the missing flight has been expanded to the Strait of Malacca and South China Sea with more countries joining in the mission.

Forty-two ships and 39 aircraft have been deployed so far in the hunt for the Boeing 777-200 plane carrying 227 passengers and 12 crew. It vanished early Saturday on its way from Kuala Lumpur to Beijing after losing contact with air traffic control in waters between Malaysia and Vietnam.

No trace of the plane has been found.